With the increase in the industrial use of electric arc welders, there is a demand for welders having output voltages between a minimum of 0-20 volts DC and a maximum of 50-100 volts DC. The welders require output currents between 100 amps and 1000 amperes. Welders rated at certain voltages and currents were separately designed. Smaller welders were constructed differently than larger welders. Most electric arc welders utilize a power supply using the topography of a DC to DC converter. Such converters are controlled by a pulse width modulation operated at a high speed pulse rate, such as 10--20 kHz. Such inverters are specially designed for either high power output or low power output. A number of inverter designs were required for a manufacturer to offer a total line of welders, especially for industrial use. Since welder manufacturers had to offer a large number of different welders having different sizes and ratings, research and development, the engineering and inventory requirements are costly and require a tremendous number of technical employees. This costly situation has been acerbated by the advent of plasma arc cutters, which units must be offered by manufacturers of electric arc welders. Although plasma arc cutters require power supplies quite similar to electric arc welders, the operating points for plasma cutters involves substantially higher output voltages with drastically lower output currents. By adding plasma arc cutters to the product line with electric arc welders, still additional design activity, inventory and service cost has been experienced. Thus, a manufacturer of electric arc welders and plasma arc cutters have several different power supplies, each of which is dedicated to a size and mode of operation for a welder or a cutter. In summary, inventory, support personnel, design personnel, inventory and service demands on a manufacturer offering a full line of electric arc welders and plasma arc cutters is substantial. Thus, only large, well capitalized manufacturers can enter into and maintain a viable competitive position in the rapidly developing field of electric arc welders and plasma arc cutters. Even such manufacturers experience decreased profits due to the high cost of maintaining a full line of products.